1. Field of the Invention
This invention relates to a tool for foaming components to a pane for a motor vehicle, especially a vehicle roof pane.
2. Description of Related Art
In tools for foaming-on of components, the problem arises that the components, on the one hand, must be held in the foaming process and, on the other hand, in the holding area, no foam should emerge from the area to be peripherally foamed. In generic foaming tools, it is well known for this purpose to provide the foaming tool with built-in rubber sealing rings, inflatable sealing elements, or milled-out recesses in the tool into which pockets of polyurethane are inserted, wherein the components are inserted into these elements.
It is a disadvantage in this process that when the components are inserted, serious friction can occur by which, on the one hand, a large amount of force must be applied and, on the other hand, distortion or bending of the component can occur upon insertion. Upon removal from the mold after the foaming process, deformations remaining in the foamed-on material can occur which leads to an adverse optical impression. On the other hand, the sealing action is often not sufficient or the insertion of the components can be unreliable due to remaining foam residues in the sealing elements. Replacement of worn sealing elements is complex and the service life of the sealing elements is relatively short. For inflatable sealing elements, investment costs are higher and a large installation space is required.
It is therefore one object of the present invention to overcome the deficiencies of the prior art and to provide a foaming tool which enables simple and low-wear insertion of the components to be foamed on.
It is another object of the present invention to provide a foaming tool which enables good sealing action and stress-free peripheral foaming.
Yet another object of the present invention is to provide a foaming tool which keeps tool costs low.
The above object and other objects are achieved in accordance with the present invention by providing a tool for foaming a component to a pane for a motor vehicle, wherein the tool forms at least one part of a boundary of an area to be peripherally foamed and comprises a rigid insert for holding the component. The rigid insert includes a bottom having an opening for insertion of an end of the component facing away from the peripheral foaming area. The tool also includes an elastic sealing ring surrounding the opening and positioned on the bottom of the rigid insert. A pressure element is provided to press the sealing ring against the bottom of the insert to deform the sealing ring in a lateral direction sufficiently to cause the sealing ring to make tight lateral contact with a part of the component which has been inserted through the opening.
The present invention is advantageous in that the components can be inserted quickly, with low friction, and free of distortion, while achieving very good sealing action with respect to the foaming material. Also, a long service life of the tool components is attained. Moreover, the dimensions when foaming-in can be reliably maintained in the process, and the tool costs are kept low. Tools can be used, without additional modifications, which are provided with a milled-out area for conventional polyurethane pockets. Furthermore, the amount of installation space required is much less than for inflatable polyurethane pockets.